#include <iostream>
#include <Eigen/Dense>
using namespace std;
using namespace Eigen;
int main()
{
    MatrixXd m(4,4),n(4,4);
    m <<1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16;
    cout<<"特征值为: \n"<<m.eigenvalues()<<endl;
    std::cout << m << std::endl;
}